From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from purkki.adurom.net ([80.68.90.206]:56143 "EHLO purkki.adurom.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752090Ab2BGQFo (ORCPT ); Tue, 7 Feb 2012 11:05:44 -0500 From: Kalle Valo To: Luciano Coelho Cc: Eliad Peller , eyal@wizery.com, linux-wireless@vger.kernel.org Subject: Re: [PATCH v2 5/7] wl12xx: add RX data filter ACX commands References: <1328021048-8944-1-git-send-email-eliad@wizery.com> <1328021048-8944-6-git-send-email-eliad@wizery.com> <1328170983.3626.265.camel@cumari> <877h00cay9.fsf@purkki.adurom.net> <1328538734.7324.139.camel@cumari> Date: Tue, 07 Feb 2012 18:05:42 +0200 In-Reply-To: <1328538734.7324.139.camel@cumari> (Luciano Coelho's message of "Mon, 06 Feb 2012 16:32:14 +0200") Message-ID: <8739amd3xl.fsf@purkki.adurom.net> (sfid-20120207_170547_941045_72459571) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Luciano Coelho writes: > On Mon, 2012-02-06 at 16:07 +0200, Kalle Valo wrote: >> Luciano Coelho writes: >> >> >> + if (index >= WL1271_MAX_RX_DATA_FILTERS) { >> >> + wl1271_warning("acx_set_rx_data_filter: invalid filter idx(%d)", >> >> + index); >> >> + return -EINVAL; >> >> + } >> > >> > Should we use BUG_ON instead? This is only used internally in the >> > driver, so if it get here, it's a bug. And if the filters come from >> > userspace, we should validate them before continuing anyway. >> >> BUG_ON() is evil and wireless drivers should really not use it, >> WARN_ON_ONCE() and return with an error is much more user friendly. > > Yeah, BUG_ON() is evil, but sometimes it can be good to have. What good does BUG_ON() bring compared to WARN_ON_ONCE()? For example, does BUG_ON() even get logged to disk? Most likely not, so WARN_ON_ONCE() is much easier to report by the users. > I don't agree with "wireless drivers should really not use it". There > are 181 occurrences in wireless-testing/master right now[1]. Then there are 181 misuses of BUG_ON() ;) > I'm not saying this measure is either accurate or an excuse to use it > where we shouldn't, but it shows that it really has widespread usage > in wireless drivers. Yes, and that's why I have started a war against misuse of BUG_ON() :) -- Kalle Valo